THE LAWS OF ORGANIC 



enne."* It is evident, from the preceding tables, 

 that rabbits of two and three months old do not 

 bear equally well the severities of winter. I have 

 not only ascertained this fact by direct experiment, 

 but I have observed its correctness, from remark- 

 ing a variety of phenomena connected with these 

 animals. If it be allowed to Dr EDWARDS, that 

 young animals, from birth to the age of fifteen 

 or thirty days, do not possess the faculty of ge- 

 nerating animal heat to a degree equal to adults, 

 how will he consistently explain the difference 

 which we observe between rabbits of three months 

 old and others full grown, on being exposed to 

 cold ? If, at three months, the faculty of generat- 

 ing heat is as perfect as at nine, what is the na- 

 ture of those circumstances which modify the ca- 

 pability of the animal for bearing diminished tem- 

 perature ? These are questions of the greatest im- 

 portance ; but they are not answered by Dr ED- 

 WARDS' views. The explanation is found in the 

 present principles. As we ascend from birth to the 

 full development of the physical powers of the 

 system, the circulation is less generally diffused, 

 or, in other words, the greater proportional quan- 

 tity is given to the internal organs for their support 

 and development. It is, therefore, obvious that 

 an animal will bear cold with a facility, cceteris 

 par 2 to, proportion ate to the extent of this change. 

 CXL. Having shown that the phenomena 

 which animals present in summer, in regard to 



* Dr EDWARDS, p. 1S6, 



